The Evidence Room, the exhibit that opened recently at the Royal Ontario Museum in Toronto, embodies Robert Jan van Pelt’s detailed and unique analysis of the Holocaust. An architectural historian at the University of Waterloo, he’s written often on the Holocaust, not only proving that it happened but that Auschwitz was carefully planned as a Nazi death site for a million Jews.

He remembers when he began teaching in the 1980s; how he was surprised to find that there were no courses in the ethics of architecture. That led him naturally to the Holocaust, the most interesting and most horrible research of his life.

Visiting Auschwitz on many occasions, studying the archived drawings of the architects who designed it, he realized he was plunging into the murky subject of “forensic architecture,” a term unknown until a few decades ago. Eventually, he was called as a witness in a famous British trial, gathering evidence that became an exhibit at the Venice biennale.

Now his research has led to the first display in the “ROM Speaks” series, events intended to create discussion of modern issues. In several rooms on the third floor of the ROM, we confront white plaster replicas of the Auschwitz killing machine, along with documents that illustrate the vile intentions of the architects.

The killing of 6 million European Jews was the greatest crime of the 20th century, perhaps the greatest single crime in history. After the Second World War, when the details became known, it was considered the worst atrocity that the Nazis undertook. It’s remembered as a profoundly dark moment in Jewish history – the Shoah, a Hebrew word meaning catastrophe.

Courtesy of the ROM

But the memory of the Holocaust took a bizarre turn when various individuals began to claim it never happened. They called it a story cooked up or vastly exaggerated by Jews in hopes of attracting financial compensation or pity. David Irving, a British writer respected as a researcher in history, came forward as a vigorous and inventive denier, soon famous for his passionate devotion to this peculiar cause.

In 1993, Deborah Lipstadt, an American academic at Emory University in Atlanta, summarized the accusations of the deniers in her book, Denying the Holocaust: The Growing Assault on Truth and Memory. She depicted this attempted rewriting of history as a form of “purely anti-Semitic diatribe.” She cited David Irving as a chief offender, which led him to sue for libel.

At the trial in 2000, she and her publisher, Penguin Books, mounted a meticulous defence that included Van Pelt’s architectural forensics. He showed, for instance, that the gas chambers were designed to be securely bolted on one side so that the victims could not escape when they realized what was happening. He identified the four openings in the roof where the Zyklon-B poison gas was dropped. This material in the ROM’s exhibit was expertly worked up at Waterloo by two architects, Donald McKay and Anne Bordeleau – both Van Pelt’s colleagues.

The story of the libel trial in London is imperfectly told in the recent film Denial, based on Lipstadt’s book, History on Trial: My Day in Court with a Holocaust Denier. The film sees the story from her side and ends agreeably with her successful defence. Rachel Weisz evokes Lipstadt’s frightened earnestness, and David Hare’s script keeps the story alive. But the director, Mick Jackson, has Timothy Spall depict Irving as a much too obvious villain, as if the audience couldn’t have developed a negative view of him on its own.

Courtesy of the ROM

The real David Irving, now 79, remains a denier – and, if you believe him, an increasingly successful one. In an interview with the Guardian he boasted that he’s now inspiring a new generation of “Holocaust skeptics.” Seventeen years ago, when he was denounced by the trial judge, his scholarly reputation was ruined and he had to declare bankruptcy. Now, apparently, interest in his work has been been rising quickly.

He told The Guardian he gets 300 to 400 emails a day and answers all of them, building relationships with the young. “I’m getting messages from 14, 15, 16-year-olds in America. There are 220 of my lectures on YouTube, I believe, and these young people tell me how they’ve stayed up all night watching them.”

This is not good news to James Libson, a solicitor for Lipstadt in her case. “We really thought the verdict marked a line in the sand,” Libson says. It appeared that Holocaust denial was finished. “We’d proven it, conclusively, in a court of law.”

Since the detailed material from the trial was published online, Libson and his colleagues thought the Internet would bolster the case against the deniers. Instead, the appalling lesson from these events has become that if a lie is imaginative, and appeals to bigots and conspiracy-lovers, it can live indefinitely.